i dont know about SRT-4s but the subaru tranny is da bizzomb...99venom runs 11s and hes still on stock tranny...you can beat it pretty bad and it will last

also as many people have said SRT4s are for straight line....traction is hard to come by when ur taking a corner at a fast speed

it all depends on what you mod....if you get a aftermarket downpipe you air conditioner warrenty will still be good...it all depends on what you mod..and Mastro Subaru is mod friendly, by what i hear